1. Field of the Invention
The invention relates to capacitors, and more specifically relates to capacitors of the wound metalized dielectric type.
2. Description of the Prior Art
A wound metalized dielectric capacitor with an integrally formed discharge resistor is disclosed in U.S. Pat. No. 4,443,829, issued on Apr. 17, 1984 to Delvy, et al. The U.S. Pat. No. 4,443,829 discloses the formation of a section of resistive material on a film forming the metalized dielectric. The resistive material extends across the film's entire width. A metal contact for one of the capacitor plates is sprayed on either end of the capacitor so as to touch one end of the section of resistive material, thereby creating a resistive shunt across the plates formed on the metalized film.
The capacitor and manufacturing process of that patent eliminated the labor-intensive manual operations involved in providing an external discharge resistor on the capacitor. Substantial economies were thereby achieved. However, the patent required the separate manufacture of a metallized film with resistive material formed thereon, which involved a labor-intensive step not encountered in the conventional capacitor manufacturing process. Also, care was required in handling the film and winding it over the capacitor core to avoid dislodging or otherwise damaging the resistive material.
Broadly, it is an object of the present invention to produce a capacitor having an integral discharge resistor and to provide a method for manufacturing the same which avoid the shortcomings of the prior art. It is specifically intended that labor intensive manufacturing procedures for incorporating the resistor in the capacitor unit be eliminated.
It is another object of the present invention to provide an integral discharge resistor in a capacitor of the wound metalized dielectric type.
It is a further object to provide an effective method for manufacturing a capacitor of the wound metalized dielectric type in such a manner as to provide an integral discharge resistor.
It is also an object of the present invention to provide a capacitor of the type described which is relatively simple and inexpensive in construction, yet reliable and convenient in use and easy to manufacture.
These objects, among others which will be discussed hereinafter, are achieved in a preferred form of the invention by providing a capacitor of the type employing a wound metalized dielectric (preferably a metalized film) with a core which is formed at least in part from a resistive material which extends across the entire width of the film (the axial dimension of the capacitor). A metal contact for one of the capacitor plates (formed by the metalization) is sprayed on either end of the capacitor so as to touch one end of resistive core, thereby creating a resistive shunt across the plates formed on the metalized film. As a result, a capacitor with an integral resistor can be manufactured without any additional steps compared to the conventional process.